Mucositis is a common inflammatory condition affecting the mucous membranes, in particular following chemotherapy or radiotherapy in patients suffering from tumours.
These types of therapy, in addition to acting on neoplastic cells, in fact also act upon the cells of healthy tissue, especially those which replicate rapidly.
As a result, the oral cavity is one of the areas which is highly affected by the complications arising from such treatment; indeed, virtually all patients treated for tumours of the head and neck, and around 40% of those subjected to radio-chemotherapy for tumours in other locations (leukaemias or lymphomas) develop complications affecting the oral cavity (Minerva Stomatol. 2002:51:173-86).
In general, the term “mucositis” is understood to mean a clinical picture characterised by the presence of reduced epithelial thickness, intense erythema and ulcers, associated with a painful symptom complex and the possible occurrence of infection and haemorrhage (Oncologist 1998:3:446-52; Oncologist 1999:11:261-6).
The biological mechanism underlying the development of mucositis, in particular oral mucositis, is subdivided into four phases: an initial inflammatory/vascular phase during which, following radio- or chemotherapy, the epithelial tissues release a large quantity of cytokines such as, for example, interleukin 1 or TNF-α, which cause the first localised tissue damage; a second epithelial phase which affects the division of the epithelial basal cells, resulting in reduced renewal of said cells, atrophy and ulceration of the tissue; a third ulcerative/bacterial phase, which is when the symptoms are at their most intense, with bacterial colonisation of the lesion. This third phase also coincides with severe neutropaenia of the patient; the fourth and final characteristic phase of mucositis is considered to be the healing phase with recovery of proliferation and differentiation of epithelial cells, a progressive increase in white cells and normalisation of the local bacterial flora.
At present, both preventive and curative treatment is provided for mucositis. In the first case, agents are used which are capable of reducing mucous absorption of the chemotherapy drugs (for example cryotherapy, allopurinol or pilocarpine etc.), agents which reduce the changes in epithelial proliferation (for example beta-carotene, glutamine or silver nitrate etc.) or antiinflammatory and antimicrobial agents (for example, mesalazine and/or chlorhexidine).
In particular, with regard to mucositis of the oral cavity, cryotherapy is today the most widely recognised preventive treatment; this method is based on the administration of ice cubes to be kept in the mouth for a period of 30 minutes with the aim of bringing about vasoconstriction of the oral mucosa in order to reduce the temperature-dependent toxicity of some chemotherapeutics. Unfortunately, cryotherapy has proved to exhibit substantial preventive effectiveness only in patients treated with chemotherapeutics which can be administered as a bolus (fluorouracils) but has proved ineffective for continuously perfused chemotherapeutics because the drug is permanently present in the circulating blood and local vasoconstriction locale is of no benefit (Oral Oncology 1999; 35:453-70).
In the second case, use is made of agents which protect the mucosa (for example, sodium bicarbonate), anaesthetic or analgesic agents (for example, lidocaine, morphine and the derivatives thereof etc.), agents which accelerate the healing process (for example, vitamin E, tretinoin, laser therapy etc.) or special diets and/or specific oral hygiene regimens.
Other methods for treating mucositis are described in US patent applications US2003/0064913 and US2003/0236217, which are incorporated herein by reference.
However, none of these preventive strategies or therapeutic approaches has proved entirely effective in the prevention or treatment of mucositis, in particular due to chemotherapy and/or radiotherapy, which remains a cause of suffering in patients suffering from tumours, such as in mucositis of the oral cavity in patients with head and/or neck tumours.
Sulglicotide is a sulfuric polyester of a glycopeptide obtained by extraction from pig duodenum. Sulglicotide is obtained by enzymatic proteolysis, repeated purification and subsequent sulfation steps; the final product is identified by electrophoresis on cellulose acetate.
Sulglicotide is a gastroprotective and antiulcer drug; it is not absorbed intestinally and is known to produce its effects only within the gastric lumen.
Indeed, sulglicotide is usually administered as a gastroprotective to individuals whose stomach wall has been attacked by drugs such as, for example, aspirin and taurocholic acid or by generic nonsteroidal antiinflammatory drugs. Clinical studies have demonstrated the effectiveness of administering sulglicotide to patients suffering from rheumatoid arthritis and receiving treatment with indomethacin and diclofenac, so preventing the occurrence of gastric or duodenal ulceration associated with the use of such nonsteroidal antiinflammatories (Scand. J. Gastroenterol. 1993; October; 28(10):875-8).
The mechanism of action, apart from being linked to pepsin inactivation, is due to the stimulation of the secretion of mucous and bicarbonate by the cells of the gastric mucosa.
In particular, sulglicotide is known to be the drug of choice for the treatment of gastric conditions associated with Helicobacter pylori inflammation.
Helicobacter pylori is a spiral-shaped, gram-negative bacterium which, thanks to its various characteristics, survives in the acidic environment of the gastric mucosa and proliferates under the mucous which coats the internal wall of the stomach, adhering to the cells of the mucosa itself. It is the cause of duodenal ulcers as well as being one of the main causes of chronic gastritis. Current treatments are based on antibiotics and, in the ever more frequent event of antibiotic-resistant strains and relapse, on specific antiulcer drugs.
Indeed, both in animal models and in various clinical studies, the administration of sulglicotide has brought about a considerable antiulcer action in the stomach, with a substantial improvement in the inflammation due to H. pylori (J. Physiol. Pharmacol. 1999 June; 50(2):197-210). Sulglicotide principally acts by inhibiting the effect of the LPS (lipopolysaccharide) produced by the bacterium which prevents somatostatin-receptor binding, causing overproduction of gastrin and acidic secretions which are responsible for the subsequent formation of the ulcer.